1. Field of the Invention
The present invention relates to an air injection device which is applicable to an air-aided fuel injection system, especially to an electromagnetic valve which is able to improve engine performance and lower fuel consumption and emission through the complete mixture and atomization of injected air and fuel injected by an injection nozzle.
2. Description of the Prior Art
The present invention relates to an electromagnetic valve device, of high speed and durability, which is applicable to an air-aided fuel injection system of an engine.
Known engine fuel injection systems can be classified into hydraulic injection systems and air-assisted fuel injection systems. For the air-assisted fuel injection system, the fuel injected from injection nozzle needs to be atomized by air for better combustion effect. Therefore, a complete atomization depends on coordination between the supplied air and fuel injection nozzle.
The valve needle and valve seat sealing positions of general transitional air injection electromagnetic valve need precision processing, and the cost of such a valve is too high in terms of its sealing ability. Besides, the use of air injection is proved to cause uncertainty of valve stroke and valve interruption due to the contamination of the valve needle by fluid pollutant.
The electromagnetic valve disclosed in U.S. Pat. No. 4,582,294 relates to a three-way solenoid valve, which is able to achieve a balance between pressure forces and to reduce magnetic force through the application of a three-way solenoid valve.
However, the three-way solenoid valve disclosed in said patent has the following defects, which render it unsuitable for an air-assisted system of an engine:
1. the sealing convex ring of the front part of armature is too high, so that the rubber distorts easily and is subject to fracture and plastic deformation; it fails to coordinate with the high frequency motion operation diaphragm.
2. The application of the diaphragm is in a rolling state.
3. The electromagnetic valve does not operate in a high frequency condition, because the electromagnetic valve is not applied to the engine injection system.
In addition, in U.S. Pat. No. 4,455,982, since the ascent of said invention is affected by the air injection of ball valve and because of its inferiority in sealing, it can not be used for a long time. Furthermore, ROC patent number 44235 teaches an electromagnetic valve in which, although there is a diaphragm, there is no convex ring with durable benefit of metals bumping, so that it is not a similar invention.
In view of the aforesaid defects caused by conventional air-aided fuel injection, this invention is intended to resolve the aforesaid defects and to make advanced improvements.